1 /*
2  * Copyright (c) 2012-2014 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/etherdevice.h>
18 #include <net/ieee80211_radiotap.h>
19 #include <linux/if_arp.h>
20 #include <linux/moduleparam.h>
21 #include <linux/ip.h>
22 #include <linux/ipv6.h>
23 #include <net/ipv6.h>
24 #include <linux/prefetch.h>
25 
26 #include "wil6210.h"
27 #include "wmi.h"
28 #include "txrx.h"
29 #include "trace.h"
30 
31 static bool rtap_include_phy_info;
32 module_param(rtap_include_phy_info, bool, S_IRUGO);
33 MODULE_PARM_DESC(rtap_include_phy_info,
34 		 " Include PHY info in the radiotap header, default - no");
35 
36 static inline int wil_vring_is_empty(struct vring *vring)
37 {
38 	return vring->swhead == vring->swtail;
39 }
40 
41 static inline u32 wil_vring_next_tail(struct vring *vring)
42 {
43 	return (vring->swtail + 1) % vring->size;
44 }
45 
46 static inline void wil_vring_advance_head(struct vring *vring, int n)
47 {
48 	vring->swhead = (vring->swhead + n) % vring->size;
49 }
50 
51 static inline int wil_vring_is_full(struct vring *vring)
52 {
53 	return wil_vring_next_tail(vring) == vring->swhead;
54 }
55 
56 /*
57  * Available space in Tx Vring
58  */
59 static inline int wil_vring_avail_tx(struct vring *vring)
60 {
61 	u32 swhead = vring->swhead;
62 	u32 swtail = vring->swtail;
63 	int used = (vring->size + swhead - swtail) % vring->size;
64 
65 	return vring->size - used - 1;
66 }
67 
68 /**
69  * wil_vring_wmark_low - low watermark for available descriptor space
70  */
71 static inline int wil_vring_wmark_low(struct vring *vring)
72 {
73 	return vring->size/8;
74 }
75 
76 /**
77  * wil_vring_wmark_high - high watermark for available descriptor space
78  */
79 static inline int wil_vring_wmark_high(struct vring *vring)
80 {
81 	return vring->size/4;
82 }
83 
84 static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
85 {
86 	struct device *dev = wil_to_dev(wil);
87 	size_t sz = vring->size * sizeof(vring->va[0]);
88 	uint i;
89 
90 	wil_dbg_misc(wil, "%s()\n", __func__);
91 
92 	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
93 
94 	vring->swhead = 0;
95 	vring->swtail = 0;
96 	vring->ctx = kcalloc(vring->size, sizeof(vring->ctx[0]), GFP_KERNEL);
97 	if (!vring->ctx) {
98 		vring->va = NULL;
99 		return -ENOMEM;
100 	}
101 	/*
102 	 * vring->va should be aligned on its size rounded up to power of 2
103 	 * This is granted by the dma_alloc_coherent
104 	 */
105 	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
106 	if (!vring->va) {
107 		kfree(vring->ctx);
108 		vring->ctx = NULL;
109 		return -ENOMEM;
110 	}
111 	/* initially, all descriptors are SW owned
112 	 * For Tx and Rx, ownership bit is at the same location, thus
113 	 * we can use any
114 	 */
115 	for (i = 0; i < vring->size; i++) {
116 		volatile struct vring_tx_desc *_d = &vring->va[i].tx;
117 
118 		_d->dma.status = TX_DMA_STATUS_DU;
119 	}
120 
121 	wil_dbg_misc(wil, "vring[%d] 0x%p:%pad 0x%p\n", vring->size,
122 		     vring->va, &vring->pa, vring->ctx);
123 
124 	return 0;
125 }
126 
127 static void wil_txdesc_unmap(struct device *dev, struct vring_tx_desc *d,
128 			     struct wil_ctx *ctx)
129 {
130 	dma_addr_t pa = wil_desc_addr(&d->dma.addr);
131 	u16 dmalen = le16_to_cpu(d->dma.length);
132 
133 	switch (ctx->mapped_as) {
134 	case wil_mapped_as_single:
135 		dma_unmap_single(dev, pa, dmalen, DMA_TO_DEVICE);
136 		break;
137 	case wil_mapped_as_page:
138 		dma_unmap_page(dev, pa, dmalen, DMA_TO_DEVICE);
139 		break;
140 	default:
141 		break;
142 	}
143 }
144 
145 static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
146 			   int tx)
147 {
148 	struct device *dev = wil_to_dev(wil);
149 	size_t sz = vring->size * sizeof(vring->va[0]);
150 
151 	if (tx) {
152 		int vring_index = vring - wil->vring_tx;
153 
154 		wil_dbg_misc(wil, "free Tx vring %d [%d] 0x%p:%pad 0x%p\n",
155 			     vring_index, vring->size, vring->va,
156 			     &vring->pa, vring->ctx);
157 	} else {
158 		wil_dbg_misc(wil, "free Rx vring [%d] 0x%p:%pad 0x%p\n",
159 			     vring->size, vring->va,
160 			     &vring->pa, vring->ctx);
161 	}
162 
163 	while (!wil_vring_is_empty(vring)) {
164 		dma_addr_t pa;
165 		u16 dmalen;
166 		struct wil_ctx *ctx;
167 
168 		if (tx) {
169 			struct vring_tx_desc dd, *d = &dd;
170 			volatile struct vring_tx_desc *_d =
171 					&vring->va[vring->swtail].tx;
172 
173 			ctx = &vring->ctx[vring->swtail];
174 			*d = *_d;
175 			wil_txdesc_unmap(dev, d, ctx);
176 			if (ctx->skb)
177 				dev_kfree_skb_any(ctx->skb);
178 			vring->swtail = wil_vring_next_tail(vring);
179 		} else { /* rx */
180 			struct vring_rx_desc dd, *d = &dd;
181 			volatile struct vring_rx_desc *_d =
182 					&vring->va[vring->swhead].rx;
183 
184 			ctx = &vring->ctx[vring->swhead];
185 			*d = *_d;
186 			pa = wil_desc_addr(&d->dma.addr);
187 			dmalen = le16_to_cpu(d->dma.length);
188 			dma_unmap_single(dev, pa, dmalen, DMA_FROM_DEVICE);
189 			kfree_skb(ctx->skb);
190 			wil_vring_advance_head(vring, 1);
191 		}
192 	}
193 	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
194 	kfree(vring->ctx);
195 	vring->pa = 0;
196 	vring->va = NULL;
197 	vring->ctx = NULL;
198 }
199 
200 /**
201  * Allocate one skb for Rx VRING
202  *
203  * Safe to call from IRQ
204  */
205 static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
206 			       u32 i, int headroom)
207 {
208 	struct device *dev = wil_to_dev(wil);
209 	unsigned int sz = RX_BUF_LEN;
210 	struct vring_rx_desc dd, *d = &dd;
211 	volatile struct vring_rx_desc *_d = &vring->va[i].rx;
212 	dma_addr_t pa;
213 
214 	/* TODO align */
215 	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
216 
217 	if (unlikely(!skb))
218 		return -ENOMEM;
219 
220 	skb_reserve(skb, headroom);
221 	skb_put(skb, sz);
222 
223 	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
224 	if (unlikely(dma_mapping_error(dev, pa))) {
225 		kfree_skb(skb);
226 		return -ENOMEM;
227 	}
228 
229 	d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
230 	wil_desc_addr_set(&d->dma.addr, pa);
231 	/* ip_length don't care */
232 	/* b11 don't care */
233 	/* error don't care */
234 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
235 	d->dma.length = cpu_to_le16(sz);
236 	*_d = *d;
237 	vring->ctx[i].skb = skb;
238 
239 	return 0;
240 }
241 
242 /**
243  * Adds radiotap header
244  *
245  * Any error indicated as "Bad FCS"
246  *
247  * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
248  *  - Rx descriptor: 32 bytes
249  *  - Phy info
250  */
251 static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
252 				       struct sk_buff *skb)
253 {
254 	struct wireless_dev *wdev = wil->wdev;
255 	struct wil6210_rtap {
256 		struct ieee80211_radiotap_header rthdr;
257 		/* fields should be in the order of bits in rthdr.it_present */
258 		/* flags */
259 		u8 flags;
260 		/* channel */
261 		__le16 chnl_freq __aligned(2);
262 		__le16 chnl_flags;
263 		/* MCS */
264 		u8 mcs_present;
265 		u8 mcs_flags;
266 		u8 mcs_index;
267 	} __packed;
268 	struct wil6210_rtap_vendor {
269 		struct wil6210_rtap rtap;
270 		/* vendor */
271 		u8 vendor_oui[3] __aligned(2);
272 		u8 vendor_ns;
273 		__le16 vendor_skip;
274 		u8 vendor_data[0];
275 	} __packed;
276 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
277 	struct wil6210_rtap_vendor *rtap_vendor;
278 	int rtap_len = sizeof(struct wil6210_rtap);
279 	int phy_length = 0; /* phy info header size, bytes */
280 	static char phy_data[128];
281 	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
282 
283 	if (rtap_include_phy_info) {
284 		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
285 		/* calculate additional length */
286 		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
287 			/**
288 			 * PHY info starts from 8-byte boundary
289 			 * there are 8-byte lines, last line may be partially
290 			 * written (HW bug), thus FW configures for last line
291 			 * to be excessive. Driver skips this last line.
292 			 */
293 			int len = min_t(int, 8 + sizeof(phy_data),
294 					wil_rxdesc_phy_length(d));
295 
296 			if (len > 8) {
297 				void *p = skb_tail_pointer(skb);
298 				void *pa = PTR_ALIGN(p, 8);
299 
300 				if (skb_tailroom(skb) >= len + (pa - p)) {
301 					phy_length = len - 8;
302 					memcpy(phy_data, pa, phy_length);
303 				}
304 			}
305 		}
306 		rtap_len += phy_length;
307 	}
308 
309 	if (skb_headroom(skb) < rtap_len &&
310 	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
311 		wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
312 		return;
313 	}
314 
315 	rtap_vendor = (void *)skb_push(skb, rtap_len);
316 	memset(rtap_vendor, 0, rtap_len);
317 
318 	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
319 	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
320 	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
321 			(1 << IEEE80211_RADIOTAP_FLAGS) |
322 			(1 << IEEE80211_RADIOTAP_CHANNEL) |
323 			(1 << IEEE80211_RADIOTAP_MCS));
324 	if (d->dma.status & RX_DMA_STATUS_ERROR)
325 		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
326 
327 	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
328 	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
329 
330 	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
331 	rtap_vendor->rtap.mcs_flags = 0;
332 	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
333 
334 	if (rtap_include_phy_info) {
335 		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
336 				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
337 		/* OUI for Wilocity 04:ce:14 */
338 		rtap_vendor->vendor_oui[0] = 0x04;
339 		rtap_vendor->vendor_oui[1] = 0xce;
340 		rtap_vendor->vendor_oui[2] = 0x14;
341 		rtap_vendor->vendor_ns = 1;
342 		/* Rx descriptor + PHY data  */
343 		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
344 						       phy_length);
345 		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
346 		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
347 		       phy_length);
348 	}
349 }
350 
351 /*
352  * Fast swap in place between 2 registers
353  */
354 static void wil_swap_u16(u16 *a, u16 *b)
355 {
356 	*a ^= *b;
357 	*b ^= *a;
358 	*a ^= *b;
359 }
360 
361 static void wil_swap_ethaddr(void *data)
362 {
363 	struct ethhdr *eth = data;
364 	u16 *s = (u16 *)eth->h_source;
365 	u16 *d = (u16 *)eth->h_dest;
366 
367 	wil_swap_u16(s++, d++);
368 	wil_swap_u16(s++, d++);
369 	wil_swap_u16(s, d);
370 }
371 
372 /**
373  * reap 1 frame from @swhead
374  *
375  * Rx descriptor copied to skb->cb
376  *
377  * Safe to call from IRQ
378  */
379 static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
380 					 struct vring *vring)
381 {
382 	struct device *dev = wil_to_dev(wil);
383 	struct net_device *ndev = wil_to_ndev(wil);
384 	volatile struct vring_rx_desc *_d;
385 	struct vring_rx_desc *d;
386 	struct sk_buff *skb;
387 	dma_addr_t pa;
388 	unsigned int sz = RX_BUF_LEN;
389 	u16 dmalen;
390 	u8 ftype;
391 	u8 ds_bits;
392 	int cid;
393 	struct wil_net_stats *stats;
394 
395 	BUILD_BUG_ON(sizeof(struct vring_rx_desc) > sizeof(skb->cb));
396 
397 	if (wil_vring_is_empty(vring))
398 		return NULL;
399 
400 	_d = &vring->va[vring->swhead].rx;
401 	if (!(_d->dma.status & RX_DMA_STATUS_DU)) {
402 		/* it is not error, we just reached end of Rx done area */
403 		return NULL;
404 	}
405 
406 	skb = vring->ctx[vring->swhead].skb;
407 	d = wil_skb_rxdesc(skb);
408 	*d = *_d;
409 	pa = wil_desc_addr(&d->dma.addr);
410 	vring->ctx[vring->swhead].skb = NULL;
411 	wil_vring_advance_head(vring, 1);
412 
413 	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
414 	dmalen = le16_to_cpu(d->dma.length);
415 
416 	trace_wil6210_rx(vring->swhead, d);
417 	wil_dbg_txrx(wil, "Rx[%3d] : %d bytes\n", vring->swhead, dmalen);
418 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_NONE, 32, 4,
419 			  (const void *)d, sizeof(*d), false);
420 
421 	if (dmalen > sz) {
422 		wil_err(wil, "Rx size too large: %d bytes!\n", dmalen);
423 		kfree_skb(skb);
424 		return NULL;
425 	}
426 	skb_trim(skb, dmalen);
427 
428 	prefetch(skb->data);
429 
430 	wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
431 			  skb->data, skb_headlen(skb), false);
432 
433 	cid = wil_rxdesc_cid(d);
434 	stats = &wil->sta[cid].stats;
435 	stats->last_mcs_rx = wil_rxdesc_mcs(d);
436 
437 	/* use radiotap header only if required */
438 	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
439 		wil_rx_add_radiotap_header(wil, skb);
440 
441 	/* no extra checks if in sniffer mode */
442 	if (ndev->type != ARPHRD_ETHER)
443 		return skb;
444 	/*
445 	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
446 	 * Driver should recognize it by frame type, that is found
447 	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
448 	 */
449 	ftype = wil_rxdesc_ftype(d) << 2;
450 	if (ftype != IEEE80211_FTYPE_DATA) {
451 		wil_dbg_txrx(wil, "Non-data frame ftype 0x%08x\n", ftype);
452 		/* TODO: process it */
453 		kfree_skb(skb);
454 		return NULL;
455 	}
456 
457 	if (skb->len < ETH_HLEN) {
458 		wil_err(wil, "Short frame, len = %d\n", skb->len);
459 		/* TODO: process it (i.e. BAR) */
460 		kfree_skb(skb);
461 		return NULL;
462 	}
463 
464 	/* L4 IDENT is on when HW calculated checksum, check status
465 	 * and in case of error drop the packet
466 	 * higher stack layers will handle retransmission (if required)
467 	 */
468 	if (d->dma.status & RX_DMA_STATUS_L4_IDENT) {
469 		/* L4 protocol identified, csum calculated */
470 		if ((d->dma.error & RX_DMA_ERROR_L4_ERR) == 0)
471 			skb->ip_summed = CHECKSUM_UNNECESSARY;
472 		/* If HW reports bad checksum, let IP stack re-check it
473 		 * For example, HW don't understand Microsoft IP stack that
474 		 * mis-calculates TCP checksum - if it should be 0x0,
475 		 * it writes 0xffff in violation of RFC 1624
476 		 */
477 	}
478 
479 	ds_bits = wil_rxdesc_ds_bits(d);
480 	if (ds_bits == 1) {
481 		/*
482 		 * HW bug - in ToDS mode, i.e. Rx on AP side,
483 		 * addresses get swapped
484 		 */
485 		wil_swap_ethaddr(skb->data);
486 	}
487 
488 	return skb;
489 }
490 
491 /**
492  * allocate and fill up to @count buffers in rx ring
493  * buffers posted at @swtail
494  */
495 static int wil_rx_refill(struct wil6210_priv *wil, int count)
496 {
497 	struct net_device *ndev = wil_to_ndev(wil);
498 	struct vring *v = &wil->vring_rx;
499 	u32 next_tail;
500 	int rc = 0;
501 	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
502 			WIL6210_RTAP_SIZE : 0;
503 
504 	for (; next_tail = wil_vring_next_tail(v),
505 			(next_tail != v->swhead) && (count-- > 0);
506 			v->swtail = next_tail) {
507 		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
508 		if (rc) {
509 			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
510 				rc, v->swtail);
511 			break;
512 		}
513 	}
514 	iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
515 
516 	return rc;
517 }
518 
519 /*
520  * Pass Rx packet to the netif. Update statistics.
521  * Called in softirq context (NAPI poll).
522  */
523 void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
524 {
525 	gro_result_t rc;
526 	struct wil6210_priv *wil = ndev_to_wil(ndev);
527 	unsigned int len = skb->len;
528 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
529 	int cid = wil_rxdesc_cid(d);
530 	struct wil_net_stats *stats = &wil->sta[cid].stats;
531 
532 	skb_orphan(skb);
533 
534 	rc = napi_gro_receive(&wil->napi_rx, skb);
535 
536 	if (unlikely(rc == GRO_DROP)) {
537 		ndev->stats.rx_dropped++;
538 		stats->rx_dropped++;
539 		wil_dbg_txrx(wil, "Rx drop %d bytes\n", len);
540 	} else {
541 		ndev->stats.rx_packets++;
542 		stats->rx_packets++;
543 		ndev->stats.rx_bytes += len;
544 		stats->rx_bytes += len;
545 	}
546 	{
547 		static const char * const gro_res_str[] = {
548 			[GRO_MERGED]		= "GRO_MERGED",
549 			[GRO_MERGED_FREE]	= "GRO_MERGED_FREE",
550 			[GRO_HELD]		= "GRO_HELD",
551 			[GRO_NORMAL]		= "GRO_NORMAL",
552 			[GRO_DROP]		= "GRO_DROP",
553 		};
554 		wil_dbg_txrx(wil, "Rx complete %d bytes => %s\n",
555 			     len, gro_res_str[rc]);
556 	}
557 }
558 
559 /**
560  * Proceed all completed skb's from Rx VRING
561  *
562  * Safe to call from NAPI poll, i.e. softirq with interrupts enabled
563  */
564 void wil_rx_handle(struct wil6210_priv *wil, int *quota)
565 {
566 	struct net_device *ndev = wil_to_ndev(wil);
567 	struct vring *v = &wil->vring_rx;
568 	struct sk_buff *skb;
569 
570 	if (!v->va) {
571 		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
572 		return;
573 	}
574 	wil_dbg_txrx(wil, "%s()\n", __func__);
575 	while ((*quota > 0) && (NULL != (skb = wil_vring_reap_rx(wil, v)))) {
576 		(*quota)--;
577 
578 		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
579 			skb->dev = ndev;
580 			skb_reset_mac_header(skb);
581 			skb->ip_summed = CHECKSUM_UNNECESSARY;
582 			skb->pkt_type = PACKET_OTHERHOST;
583 			skb->protocol = htons(ETH_P_802_2);
584 			wil_netif_rx_any(skb, ndev);
585 		} else {
586 			struct ethhdr *eth = (void *)skb->data;
587 
588 			skb->protocol = eth_type_trans(skb, ndev);
589 
590 			if (is_unicast_ether_addr(eth->h_dest))
591 				wil_rx_reorder(wil, skb);
592 			else
593 				wil_netif_rx_any(skb, ndev);
594 		}
595 	}
596 	wil_rx_refill(wil, v->size);
597 }
598 
599 int wil_rx_init(struct wil6210_priv *wil)
600 {
601 	struct vring *vring = &wil->vring_rx;
602 	int rc;
603 
604 	wil_dbg_misc(wil, "%s()\n", __func__);
605 
606 	if (vring->va) {
607 		wil_err(wil, "Rx ring already allocated\n");
608 		return -EINVAL;
609 	}
610 
611 	vring->size = WIL6210_RX_RING_SIZE;
612 	rc = wil_vring_alloc(wil, vring);
613 	if (rc)
614 		return rc;
615 
616 	rc = wmi_rx_chain_add(wil, vring);
617 	if (rc)
618 		goto err_free;
619 
620 	rc = wil_rx_refill(wil, vring->size);
621 	if (rc)
622 		goto err_free;
623 
624 	return 0;
625  err_free:
626 	wil_vring_free(wil, vring, 0);
627 
628 	return rc;
629 }
630 
631 void wil_rx_fini(struct wil6210_priv *wil)
632 {
633 	struct vring *vring = &wil->vring_rx;
634 
635 	wil_dbg_misc(wil, "%s()\n", __func__);
636 
637 	if (vring->va)
638 		wil_vring_free(wil, vring, 0);
639 }
640 
641 int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
642 		      int cid, int tid)
643 {
644 	int rc;
645 	struct wmi_vring_cfg_cmd cmd = {
646 		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
647 		.vring_cfg = {
648 			.tx_sw_ring = {
649 				.max_mpdu_size = cpu_to_le16(TX_BUF_LEN),
650 				.ring_size = cpu_to_le16(size),
651 			},
652 			.ringid = id,
653 			.cidxtid = mk_cidxtid(cid, tid),
654 			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
655 			.mac_ctrl = 0,
656 			.to_resolution = 0,
657 			.agg_max_wsize = 16,
658 			.schd_params = {
659 				.priority = cpu_to_le16(0),
660 				.timeslot_us = cpu_to_le16(0xfff),
661 			},
662 		},
663 	};
664 	struct {
665 		struct wil6210_mbox_hdr_wmi wmi;
666 		struct wmi_vring_cfg_done_event cmd;
667 	} __packed reply;
668 	struct vring *vring = &wil->vring_tx[id];
669 	struct vring_tx_data *txdata = &wil->vring_tx_data[id];
670 
671 	wil_dbg_misc(wil, "%s() max_mpdu_size %d\n", __func__,
672 		     cmd.vring_cfg.tx_sw_ring.max_mpdu_size);
673 
674 	if (vring->va) {
675 		wil_err(wil, "Tx ring [%d] already allocated\n", id);
676 		rc = -EINVAL;
677 		goto out;
678 	}
679 
680 	memset(txdata, 0, sizeof(*txdata));
681 	vring->size = size;
682 	rc = wil_vring_alloc(wil, vring);
683 	if (rc)
684 		goto out;
685 
686 	wil->vring2cid_tid[id][0] = cid;
687 	wil->vring2cid_tid[id][1] = tid;
688 
689 	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
690 
691 	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
692 		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
693 	if (rc)
694 		goto out_free;
695 
696 	if (reply.cmd.status != WMI_FW_STATUS_SUCCESS) {
697 		wil_err(wil, "Tx config failed, status 0x%02x\n",
698 			reply.cmd.status);
699 		rc = -EINVAL;
700 		goto out_free;
701 	}
702 	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
703 
704 	txdata->enabled = 1;
705 
706 	return 0;
707  out_free:
708 	wil_vring_free(wil, vring, 1);
709  out:
710 
711 	return rc;
712 }
713 
714 void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
715 {
716 	struct vring *vring = &wil->vring_tx[id];
717 
718 	WARN_ON(!mutex_is_locked(&wil->mutex));
719 
720 	if (!vring->va)
721 		return;
722 
723 	wil_dbg_misc(wil, "%s() id=%d\n", __func__, id);
724 
725 	/* make sure NAPI won't touch this vring */
726 	wil->vring_tx_data[id].enabled = 0;
727 	if (test_bit(wil_status_napi_en, &wil->status))
728 		napi_synchronize(&wil->napi_tx);
729 
730 	wil_vring_free(wil, vring, 1);
731 }
732 
733 static struct vring *wil_find_tx_vring(struct wil6210_priv *wil,
734 				       struct sk_buff *skb)
735 {
736 	int i;
737 	struct ethhdr *eth = (void *)skb->data;
738 	int cid = wil_find_cid(wil, eth->h_dest);
739 
740 	if (cid < 0)
741 		return NULL;
742 
743 	if (!wil->sta[cid].data_port_open &&
744 	    (skb->protocol != cpu_to_be16(ETH_P_PAE)))
745 		return NULL;
746 
747 	/* TODO: fix for multiple TID */
748 	for (i = 0; i < ARRAY_SIZE(wil->vring2cid_tid); i++) {
749 		if (wil->vring2cid_tid[i][0] == cid) {
750 			struct vring *v = &wil->vring_tx[i];
751 
752 			wil_dbg_txrx(wil, "%s(%pM) -> [%d]\n",
753 				     __func__, eth->h_dest, i);
754 			if (v->va) {
755 				return v;
756 			} else {
757 				wil_dbg_txrx(wil, "vring[%d] not valid\n", i);
758 				return NULL;
759 			}
760 		}
761 	}
762 
763 	return NULL;
764 }
765 
766 static void wil_set_da_for_vring(struct wil6210_priv *wil,
767 				 struct sk_buff *skb, int vring_index)
768 {
769 	struct ethhdr *eth = (void *)skb->data;
770 	int cid = wil->vring2cid_tid[vring_index][0];
771 
772 	memcpy(eth->h_dest, wil->sta[cid].addr, ETH_ALEN);
773 }
774 
775 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
776 			struct sk_buff *skb);
777 /*
778  * Find 1-st vring and return it; set dest address for this vring in skb
779  * duplicate skb and send it to other active vrings
780  */
781 static struct vring *wil_tx_bcast(struct wil6210_priv *wil,
782 				  struct sk_buff *skb)
783 {
784 	struct vring *v, *v2;
785 	struct sk_buff *skb2;
786 	int i;
787 	u8 cid;
788 
789 	/* find 1-st vring eligible for data */
790 	for (i = 0; i < WIL6210_MAX_TX_RINGS; i++) {
791 		v = &wil->vring_tx[i];
792 		if (!v->va)
793 			continue;
794 
795 		cid = wil->vring2cid_tid[i][0];
796 		if (!wil->sta[cid].data_port_open)
797 			continue;
798 
799 		goto found;
800 	}
801 
802 	wil_dbg_txrx(wil, "Tx while no vrings active?\n");
803 
804 	return NULL;
805 
806 found:
807 	wil_dbg_txrx(wil, "BCAST -> ring %d\n", i);
808 	wil_set_da_for_vring(wil, skb, i);
809 
810 	/* find other active vrings and duplicate skb for each */
811 	for (i++; i < WIL6210_MAX_TX_RINGS; i++) {
812 		v2 = &wil->vring_tx[i];
813 		if (!v2->va)
814 			continue;
815 		cid = wil->vring2cid_tid[i][0];
816 		if (!wil->sta[cid].data_port_open)
817 			continue;
818 
819 		skb2 = skb_copy(skb, GFP_ATOMIC);
820 		if (skb2) {
821 			wil_dbg_txrx(wil, "BCAST DUP -> ring %d\n", i);
822 			wil_set_da_for_vring(wil, skb2, i);
823 			wil_tx_vring(wil, v2, skb2);
824 		} else {
825 			wil_err(wil, "skb_copy failed\n");
826 		}
827 	}
828 
829 	return v;
830 }
831 
832 static int wil_tx_desc_map(struct vring_tx_desc *d, dma_addr_t pa, u32 len,
833 			   int vring_index)
834 {
835 	wil_desc_addr_set(&d->dma.addr, pa);
836 	d->dma.ip_length = 0;
837 	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
838 	d->dma.b11 = 0/*14 | BIT(7)*/;
839 	d->dma.error = 0;
840 	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
841 	d->dma.length = cpu_to_le16((u16)len);
842 	d->dma.d0 = (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
843 	d->mac.d[0] = 0;
844 	d->mac.d[1] = 0;
845 	d->mac.d[2] = 0;
846 	d->mac.ucode_cmd = 0;
847 	/* use dst index 0 */
848 	d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_DST_INDEX_EN_POS) |
849 		       (0 << MAC_CFG_DESC_TX_1_DST_INDEX_POS);
850 	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
851 	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
852 		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
853 
854 	return 0;
855 }
856 
857 static inline
858 void wil_tx_desc_set_nr_frags(struct vring_tx_desc *d, int nr_frags)
859 {
860 	d->mac.d[2] |= ((nr_frags + 1) <<
861 		       MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
862 }
863 
864 static int wil_tx_desc_offload_cksum_set(struct wil6210_priv *wil,
865 					 struct vring_tx_desc *d,
866 					 struct sk_buff *skb)
867 {
868 	int protocol;
869 
870 	if (skb->ip_summed != CHECKSUM_PARTIAL)
871 		return 0;
872 
873 	d->dma.b11 = ETH_HLEN; /* MAC header length */
874 
875 	switch (skb->protocol) {
876 	case cpu_to_be16(ETH_P_IP):
877 		protocol = ip_hdr(skb)->protocol;
878 		d->dma.b11 |= BIT(DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS);
879 		break;
880 	case cpu_to_be16(ETH_P_IPV6):
881 		protocol = ipv6_hdr(skb)->nexthdr;
882 		break;
883 	default:
884 		return -EINVAL;
885 	}
886 
887 	switch (protocol) {
888 	case IPPROTO_TCP:
889 		d->dma.d0 |= (2 << DMA_CFG_DESC_TX_0_L4_TYPE_POS);
890 		/* L4 header len: TCP header length */
891 		d->dma.d0 |=
892 		(tcp_hdrlen(skb) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
893 		break;
894 	case IPPROTO_UDP:
895 		/* L4 header len: UDP header length */
896 		d->dma.d0 |=
897 		(sizeof(struct udphdr) & DMA_CFG_DESC_TX_0_L4_LENGTH_MSK);
898 		break;
899 	default:
900 		return -EINVAL;
901 	}
902 
903 	d->dma.ip_length = skb_network_header_len(skb);
904 	/* Enable TCP/UDP checksum */
905 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_TCP_UDP_CHECKSUM_EN_POS);
906 	/* Calculate pseudo-header */
907 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_PSEUDO_HEADER_CALC_EN_POS);
908 
909 	return 0;
910 }
911 
912 static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
913 			struct sk_buff *skb)
914 {
915 	struct device *dev = wil_to_dev(wil);
916 	struct vring_tx_desc dd, *d = &dd;
917 	volatile struct vring_tx_desc *_d;
918 	u32 swhead = vring->swhead;
919 	int avail = wil_vring_avail_tx(vring);
920 	int nr_frags = skb_shinfo(skb)->nr_frags;
921 	uint f = 0;
922 	int vring_index = vring - wil->vring_tx;
923 	struct vring_tx_data *txdata = &wil->vring_tx_data[vring_index];
924 	uint i = swhead;
925 	dma_addr_t pa;
926 
927 	wil_dbg_txrx(wil, "%s()\n", __func__);
928 
929 	if (avail < 1 + nr_frags) {
930 		wil_err(wil, "Tx ring full. No space for %d fragments\n",
931 			1 + nr_frags);
932 		return -ENOMEM;
933 	}
934 	_d = &vring->va[i].tx;
935 
936 	pa = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
937 
938 	wil_dbg_txrx(wil, "Tx skb %d bytes 0x%p -> %pad\n", skb_headlen(skb),
939 		     skb->data, &pa);
940 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
941 			  skb->data, skb_headlen(skb), false);
942 
943 	if (unlikely(dma_mapping_error(dev, pa)))
944 		return -EINVAL;
945 	vring->ctx[i].mapped_as = wil_mapped_as_single;
946 	/* 1-st segment */
947 	wil_tx_desc_map(d, pa, skb_headlen(skb), vring_index);
948 	/* Process TCP/UDP checksum offloading */
949 	if (wil_tx_desc_offload_cksum_set(wil, d, skb)) {
950 		wil_err(wil, "VRING #%d Failed to set cksum, drop packet\n",
951 			vring_index);
952 		goto dma_error;
953 	}
954 
955 	vring->ctx[i].nr_frags = nr_frags;
956 	wil_tx_desc_set_nr_frags(d, nr_frags);
957 	if (nr_frags)
958 		*_d = *d;
959 
960 	/* middle segments */
961 	for (; f < nr_frags; f++) {
962 		const struct skb_frag_struct *frag =
963 				&skb_shinfo(skb)->frags[f];
964 		int len = skb_frag_size(frag);
965 
966 		i = (swhead + f + 1) % vring->size;
967 		_d = &vring->va[i].tx;
968 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
969 				      DMA_TO_DEVICE);
970 		if (unlikely(dma_mapping_error(dev, pa)))
971 			goto dma_error;
972 		vring->ctx[i].mapped_as = wil_mapped_as_page;
973 		wil_tx_desc_map(d, pa, len, vring_index);
974 		/* no need to check return code -
975 		 * if it succeeded for 1-st descriptor,
976 		 * it will succeed here too
977 		 */
978 		wil_tx_desc_offload_cksum_set(wil, d, skb);
979 		*_d = *d;
980 	}
981 	/* for the last seg only */
982 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
983 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_MARK_WB_POS);
984 	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
985 	*_d = *d;
986 
987 	/* hold reference to skb
988 	 * to prevent skb release before accounting
989 	 * in case of immediate "tx done"
990 	 */
991 	vring->ctx[i].skb = skb_get(skb);
992 
993 	wil_hex_dump_txrx("Tx ", DUMP_PREFIX_NONE, 32, 4,
994 			  (const void *)d, sizeof(*d), false);
995 
996 	if (wil_vring_is_empty(vring)) /* performance monitoring */
997 		txdata->idle += get_cycles() - txdata->last_idle;
998 
999 	/* advance swhead */
1000 	wil_vring_advance_head(vring, nr_frags + 1);
1001 	wil_dbg_txrx(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
1002 	trace_wil6210_tx(vring_index, swhead, skb->len, nr_frags);
1003 	iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
1004 
1005 	return 0;
1006  dma_error:
1007 	/* unmap what we have mapped */
1008 	nr_frags = f + 1; /* frags mapped + one for skb head */
1009 	for (f = 0; f < nr_frags; f++) {
1010 		struct wil_ctx *ctx;
1011 
1012 		i = (swhead + f) % vring->size;
1013 		ctx = &vring->ctx[i];
1014 		_d = &vring->va[i].tx;
1015 		*d = *_d;
1016 		_d->dma.status = TX_DMA_STATUS_DU;
1017 		wil_txdesc_unmap(dev, d, ctx);
1018 
1019 		if (ctx->skb)
1020 			dev_kfree_skb_any(ctx->skb);
1021 
1022 		memset(ctx, 0, sizeof(*ctx));
1023 	}
1024 
1025 	return -EINVAL;
1026 }
1027 
1028 netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
1029 {
1030 	struct wil6210_priv *wil = ndev_to_wil(ndev);
1031 	struct ethhdr *eth = (void *)skb->data;
1032 	struct vring *vring;
1033 	static bool pr_once_fw;
1034 	int rc;
1035 
1036 	wil_dbg_txrx(wil, "%s()\n", __func__);
1037 	if (!test_bit(wil_status_fwready, &wil->status)) {
1038 		if (!pr_once_fw) {
1039 			wil_err(wil, "FW not ready\n");
1040 			pr_once_fw = true;
1041 		}
1042 		goto drop;
1043 	}
1044 	if (!test_bit(wil_status_fwconnected, &wil->status)) {
1045 		wil_err(wil, "FW not connected\n");
1046 		goto drop;
1047 	}
1048 	if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
1049 		wil_err(wil, "Xmit in monitor mode not supported\n");
1050 		goto drop;
1051 	}
1052 	pr_once_fw = false;
1053 
1054 	/* find vring */
1055 	if (is_unicast_ether_addr(eth->h_dest))
1056 		vring = wil_find_tx_vring(wil, skb);
1057 	else
1058 		vring = wil_tx_bcast(wil, skb);
1059 	if (!vring) {
1060 		wil_dbg_txrx(wil, "No Tx VRING found for %pM\n", eth->h_dest);
1061 		goto drop;
1062 	}
1063 
1064 	/* set up vring entry */
1065 	rc = wil_tx_vring(wil, vring, skb);
1066 
1067 	/* do we still have enough room in the vring? */
1068 	if (wil_vring_avail_tx(vring) < wil_vring_wmark_low(vring)) {
1069 		netif_tx_stop_all_queues(wil_to_ndev(wil));
1070 		wil_dbg_txrx(wil, "netif_tx_stop : ring full\n");
1071 	}
1072 
1073 	switch (rc) {
1074 	case 0:
1075 		/* statistics will be updated on the tx_complete */
1076 		dev_kfree_skb_any(skb);
1077 		return NETDEV_TX_OK;
1078 	case -ENOMEM:
1079 		return NETDEV_TX_BUSY;
1080 	default:
1081 		break; /* goto drop; */
1082 	}
1083  drop:
1084 	ndev->stats.tx_dropped++;
1085 	dev_kfree_skb_any(skb);
1086 
1087 	return NET_XMIT_DROP;
1088 }
1089 
1090 /**
1091  * Clean up transmitted skb's from the Tx VRING
1092  *
1093  * Return number of descriptors cleared
1094  *
1095  * Safe to call from IRQ
1096  */
1097 int wil_tx_complete(struct wil6210_priv *wil, int ringid)
1098 {
1099 	struct net_device *ndev = wil_to_ndev(wil);
1100 	struct device *dev = wil_to_dev(wil);
1101 	struct vring *vring = &wil->vring_tx[ringid];
1102 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
1103 	int done = 0;
1104 	int cid = wil->vring2cid_tid[ringid][0];
1105 	struct wil_net_stats *stats = &wil->sta[cid].stats;
1106 	volatile struct vring_tx_desc *_d;
1107 
1108 	if (!vring->va) {
1109 		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
1110 		return 0;
1111 	}
1112 
1113 	if (!txdata->enabled) {
1114 		wil_info(wil, "Tx irq[%d]: vring disabled\n", ringid);
1115 		return 0;
1116 	}
1117 
1118 	wil_dbg_txrx(wil, "%s(%d)\n", __func__, ringid);
1119 
1120 	while (!wil_vring_is_empty(vring)) {
1121 		int new_swtail;
1122 		struct wil_ctx *ctx = &vring->ctx[vring->swtail];
1123 		/**
1124 		 * For the fragmented skb, HW will set DU bit only for the
1125 		 * last fragment. look for it
1126 		 */
1127 		int lf = (vring->swtail + ctx->nr_frags) % vring->size;
1128 		/* TODO: check we are not past head */
1129 
1130 		_d = &vring->va[lf].tx;
1131 		if (!(_d->dma.status & TX_DMA_STATUS_DU))
1132 			break;
1133 
1134 		new_swtail = (lf + 1) % vring->size;
1135 		while (vring->swtail != new_swtail) {
1136 			struct vring_tx_desc dd, *d = &dd;
1137 			u16 dmalen;
1138 			struct sk_buff *skb;
1139 
1140 			ctx = &vring->ctx[vring->swtail];
1141 			skb = ctx->skb;
1142 			_d = &vring->va[vring->swtail].tx;
1143 
1144 			*d = *_d;
1145 
1146 			dmalen = le16_to_cpu(d->dma.length);
1147 			trace_wil6210_tx_done(ringid, vring->swtail, dmalen,
1148 					      d->dma.error);
1149 			wil_dbg_txrx(wil,
1150 				     "Tx[%3d] : %d bytes, status 0x%02x err 0x%02x\n",
1151 				     vring->swtail, dmalen, d->dma.status,
1152 				     d->dma.error);
1153 			wil_hex_dump_txrx("TxC ", DUMP_PREFIX_NONE, 32, 4,
1154 					  (const void *)d, sizeof(*d), false);
1155 
1156 			wil_txdesc_unmap(dev, d, ctx);
1157 
1158 			if (skb) {
1159 				if (d->dma.error == 0) {
1160 					ndev->stats.tx_packets++;
1161 					stats->tx_packets++;
1162 					ndev->stats.tx_bytes += skb->len;
1163 					stats->tx_bytes += skb->len;
1164 				} else {
1165 					ndev->stats.tx_errors++;
1166 					stats->tx_errors++;
1167 				}
1168 
1169 				dev_kfree_skb_any(skb);
1170 			}
1171 			memset(ctx, 0, sizeof(*ctx));
1172 			/* There is no need to touch HW descriptor:
1173 			 * - ststus bit TX_DMA_STATUS_DU is set by design,
1174 			 *   so hardware will not try to process this desc.,
1175 			 * - rest of descriptor will be initialized on Tx.
1176 			 */
1177 			vring->swtail = wil_vring_next_tail(vring);
1178 			done++;
1179 		}
1180 	}
1181 
1182 	if (wil_vring_is_empty(vring)) { /* performance monitoring */
1183 		wil_dbg_txrx(wil, "Ring[%2d] empty\n", ringid);
1184 		txdata->last_idle = get_cycles();
1185 	}
1186 
1187 	if (wil_vring_avail_tx(vring) > wil_vring_wmark_high(vring)) {
1188 		wil_dbg_txrx(wil, "netif_tx_wake : ring not full\n");
1189 		netif_tx_wake_all_queues(wil_to_ndev(wil));
1190 	}
1191 
1192 	return done;
1193 }
1194